Eukaryotic cells direct proteins to various subcellular locations by exploiting physical differences between organelles. However, in specific instances during cellular morphogenesis in bacteria, there is no obvious basis for subcellular discrimination by which the cell could determine the proper final destination of a protein. The establishment of the asymmetric cell division site of Bacillus subtilis during sporulation and the subsequent targeting of proteins to the sporulation septum represent such a situation. We will study the localization of the protein SpolVFA, which localizes to the septal membrane at the onset of sporulation. First, we will identify the localization signal of SpolVFA and characterize it by mutational analysis. Next we will elucidate the mechanism by which SpolVFA is sorted by examining whether it is directly inserted at the septal membrane or is targeted to the septum by lateral diffusion after general insertion into the plasma membrane. Finally, we will identify extragenic factors that mediate the proper sorting of SpolVFA. Our findings will seek to explain what landmark subcellular features bacteria discern in order to identify target locations for sorted proteins. [unreadable] [unreadable]